package javax;

public class Xp_0101 {
    //合并两个有序链表
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        if (l1 == null && l2 == null){
            return null;
        }
        if (l1 == null){
            return l2;
        }
        if (l2 == null){
            return l1;
        }
        ListNode head = null;
        if (l1.val > l2.val) {
            head = l2;
            head.next = mergeTwoLists(l1, l2.next);
        } else {
            head = l1;
            head.next = mergeTwoLists(l1.next, l2);
        }
        return head;
    }

    public class ListNode {
        int val;
        ListNode next = null;

        ListNode(int val) {
            this.val = val;
        }
    }

    public static void main(String[] args) {
//        ListNode listNode = {};
    }

}
